A television terminal and the like included in a teleconference system has a camera (image capturing apparatus) for shooting a scene in a meeting. This camera may be used not only for shooting a scene in a meeting, but also for capturing a manuscript, a drawing, and a whiteboard so that such information can be shared with a peer. Desired for such an application is an image transformation process, for example, for focusing on a partial area in a shot image and displaying an enlarged image of the area (digital zooming), or for correcting the image of a manuscript, a drawing, or a whiteboard shot from a diagonal angle so as to enable the image to appear as if the image is shot directly from the front side (perspective correction). Concerning to this issue, image transformation processing techniques such as digital zooming and a perspective correction for digital cameras are already known (Japanese Patent Application Laid-open No. 2004-72181 and Japanese Patent Application Laid-open No. 2008-60827, for example).
However, in the conventional image transformation processing techniques, when the digital zooming or the perspective correction is to be applied to sequential frame images, such as a video or an animation, in real time, it has been difficult to implement an image capturing apparatus with hardware such as an image signal processor (ISP) having every functions required for the processes. For example, to explain about the perspective correction, to perform the process for automatically detecting, from a shot image, an area (having a quadrangular shape) corresponding to a manuscript, a drawing, and a whiteboard that is a subject, the entire image has to be retrieved. Therefore, the process becomes relatively complex, and also requires a long processing time. Thus, to apply the process to a video or an animation, a hardware implementation using an ISP has been difficult or impossible.
The present invention has been made to enable an image transformation to be performed in real time to sequential frame images, such as a video and an animation, using an ISP and the like in an image capturing apparatus, and to speed up and to streamline the image transformation.
Specifically, an object of the present invention is to provide a video processing apparatus, a video processing system, a teleconference system, a remote surveillance system, a video processing method, and an image capturing apparatus that can speed up and streamline the image transformation.